http3: return the context cancellation error from RoundTrip

http3/client.go

@@ -254,6 +254,15 @@ func (c *client) maxHeaderBytes() uint64 {
 
 // RoundTripOpt executes a request and returns a response
 func (c *client) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
+ rsp, err := c.roundTripOpt(req, opt)
+ if err != nil && req.Context().Err() != nil {
+ // if the context was canceled, return the context cancellation error
+ err = req.Context().Err()
+ }
+ return rsp, err
+}
+
+func (c *client) roundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
  if authorityAddr("https", hostnameFromRequest(req)) != c.hostname {
  return nil, fmt.Errorf("http3 client BUG: RoundTripOpt called for the wrong client (expected %s, got %s)", c.hostname, req.Host)
  }

http3/client_test.go

@@ -922,7 +922,7 @@ var _ = Describe("Client", func() {
  return 0, errors.New("test done")
  })
  _, err := cl.RoundTripOpt(req, roundTripOpt)
- Expect(err).To(MatchError("test done"))
+ Expect(err).To(MatchError(context.Canceled))
  Eventually(done).Should(BeClosed())
  })
  })

integrationtests/self/http_test.go

@@ -299,6 +299,21 @@ var _ = Describe("HTTP tests", func() {
  Expect(string(body)).To(Equal("Hello, World!\n"))
  })
 
+ It("handles context cancellations", func() {
+ mux.HandleFunc("/cancel", func(w http.ResponseWriter, r *http.Request) {
+ <-r.Context().Done()
+ })
+
+ ctx, cancel := context.WithCancel(context.Background())
+ req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("https://localhost:%d/cancel", port), nil)
+ Expect(err).ToNot(HaveOccurred())
+ time.AfterFunc(50*time.Millisecond, cancel)
+
+ _, err = client.Do(req)
+ Expect(err).To(HaveOccurred())
+ Expect(err).To(MatchError(context.Canceled))
+ })
+
  It("cancels requests", func() {
  handlerCalled := make(chan struct{})
  mux.HandleFunc("/cancel", func(w http.ResponseWriter, r *http.Request) {